#include "git-compat-util.h"

#include "config.h"

#include "dir.h"

#include "tr2_sysenv.h"

/*

 * Each entry represents a trace2 setting.

 * See Documentation/technical/api-trace2.txt

 */

struct tr2_sysenv_entry {

  const char *env_var_name;

  const char *git_config_name;

  char *value;

  unsigned int getenv_called : 1;

};

/*

 * This table must match "enum tr2_sysenv_variable" in tr2_sysenv.h.

 *

 * The strings in this table are constant and must match the published

 * config and environment variable names as described in the documentation.

 *

 * We do not define entries for the GIT_TRACE2_PARENT_* environment

 * variables because they are transient and used to pass information

 * from parent to child git processes, rather than settings.

 */

/* clang-format off */

static struct tr2_sysenv_entry tr2_sysenv_settings[] = {

  [TR2_SYSENV_CFG_PARAM]     = { "GIT_TRACE2_CONFIG_PARAMS",

               "trace2.configparams" },

  [TR2_SYSENV_ENV_VARS]      = { "GIT_TRACE2_ENV_VARS",

               "trace2.envvars" },

  [TR2_SYSENV_DST_DEBUG]     = { "GIT_TRACE2_DST_DEBUG",

               "trace2.destinationdebug" },

  [TR2_SYSENV_NORMAL]        = { "GIT_TRACE2",

               "trace2.normaltarget" },

  [TR2_SYSENV_NORMAL_BRIEF]  = { "GIT_TRACE2_BRIEF",

               "trace2.normalbrief" },

  [TR2_SYSENV_EVENT]         = { "GIT_TRACE2_EVENT",

               "trace2.eventtarget" },

  [TR2_SYSENV_EVENT_BRIEF]   = { "GIT_TRACE2_EVENT_BRIEF",

               "trace2.eventbrief" },

  [TR2_SYSENV_EVENT_NESTING] = { "GIT_TRACE2_EVENT_NESTING",

               "trace2.eventnesting" },

  [TR2_SYSENV_PERF]          = { "GIT_TRACE2_PERF",

               "trace2.perftarget" },

  [TR2_SYSENV_PERF_BRIEF]    = { "GIT_TRACE2_PERF_BRIEF",

               "trace2.perfbrief" },

  [TR2_SYSENV_MAX_FILES]     = { "GIT_TRACE2_MAX_FILES",

               "trace2.maxfiles" },

};

/* clang-format on */

static int tr2_sysenv_cb(const char *key, const char *value,

       const struct config_context *ctx UNUSED,

       void *d UNUSED)

{

  int k;

  if (!starts_with(key, "trace2."))

    return 0;

  for (k = 0; k < ARRAY_SIZE(tr2_sysenv_settings); k++) {

    if (!strcmp(key, tr2_sysenv_settings[k].git_config_name)) {

      if (!value)

        return config_error_nonbool(key);

      free(tr2_sysenv_settings[k].value);

      tr2_sysenv_settings[k].value = xstrdup(value);

      return 0;

    }

  }

  return 0;

}

/*

 * Load Trace2 settings from the system config (usually "/etc/gitconfig"

 * unless we were built with a runtime-prefix).  These are intended to

 * define the default values for Trace2 as requested by the administrator.

 *

 * Then override with the Trace2 settings from the global config.

 */

void tr2_sysenv_load(void)

{

  if (ARRAY_SIZE(tr2_sysenv_settings) != TR2_SYSENV_MUST_BE_LAST)

    BUG("tr2_sysenv_settings size is wrong");

  read_very_early_config(tr2_sysenv_cb, NULL);

}

/*

 * Return the value for the requested Trace2 setting from these sources:

 * the system config, the global config, and the environment.

 */

const char *tr2_sysenv_get(enum tr2_sysenv_variable var)

{

  if (var >= TR2_SYSENV_MUST_BE_LAST)

    BUG("tr2_sysenv_get invalid var '%d'", var);

  if (!tr2_sysenv_settings[var].getenv_called) {

    const char *v = getenv(tr2_sysenv_settings[var].env_var_name);

    if (v && *v) {

      free(tr2_sysenv_settings[var].value);

      tr2_sysenv_settings[var].value = xstrdup(v);

    }

    tr2_sysenv_settings[var].getenv_called = 1;

  }

  return tr2_sysenv_settings[var].value;

}

/*

 * Return a friendly name for this setting that is suitable for printing

 * in an error messages.

 */

const char *tr2_sysenv_display_name(enum tr2_sysenv_variable var)

{

  if (var >= TR2_SYSENV_MUST_BE_LAST)

    BUG("tr2_sysenv_get invalid var '%d'", var);

  return tr2_sysenv_settings[var].env_var_name;

}

void tr2_sysenv_release(void)

{

  int k;

  for (k = 0; k < ARRAY_SIZE(tr2_sysenv_settings); k++)

    free(tr2_sysenv_settings[k].value);

}